Natural gas generally refers to light gaseous hydrocarbons, and especially comprising methane. Natural gas also contains hydrocarbons such as ethane, propane, butanes, and the like, along with inert components, such as nitrogen, argon, and carbon dioxide. Natural gas is recovered from underground reservoirs, and is commonly used as an energy source for heating and power generation. Typically, natural gas is recovered at high pressure, processed, and fed into a gas pipeline under pressure.
As gas wells age and their natural pressure drops, oxygen infiltration becomes more of a problem. It is well known that oxygen contamination of natural gas used for regeneration of the molecular sieve drying unit can lead to damage of the molecular sieves through combustion of residual heavy hydrocarbon. Oxygen can easily be removed from natural gas using a transition metal based adsorbent, such as a copper based adsorbent. Reduced copper can decrease the oxygen concentration to very low levels at ambient temperature.
The copper based adsorbent is regenerable provided a suitable reducing gas can be obtained. Unfortunately, most natural gas facilities do not have a stream capable of reducing CuO at temperatures below 287.8° C. (550° F.), the maximum temperature usually available in natural gas plants.
Therefore, there is a need for processes for treating natural gas to remove oxygen at the lower temperatures available in natural gas processing plants.